Brief Overview

Potassium triiodide is a dark brown-violet solution of potassium iodide with iodine in water. A small amount may be used for emergency disinfection of drinking water.

Manufacturing Process

The most commonly used (nominal) 5% solution consists of 5% (wt/v) metallic iodine (I2) and 10% (wt/v) potassium iodide (KI) mixed in distilled water, and has a total iodine content of 126.4 mg/mL. The iodide combines with metallic iodine to form a high concentration of potassium triiodide (KI3) solution. There is some excess potassium.

Medical Industry

• Reagent added to the vagina and cervix during colposcopy
• Reagent used to better visualize the mucogingival junction in the mouth
• Oxidizing germicide which is washed off with 70% ethanol solution to avoid scarring and discoloration of the skin
• Reagent used to arrest the flow of blood

Science Industry

• Dye fixative when performing a Gram stain
• Indicator test for the presence of starches in organic compounds
• Cell stain used to make the cell nuclei more visible and to preserve phytoplankton samples
• Reagent used in experiments to observe how a cell membrane uses osmosis and diffusion

Marine Industry

• Agent used to help rid the animals of unwanted parasites and harmful bacteria

Other Applications

• Disinfectant to small wounds
• Coloring agent in inks and paint

Water Treatment Industry

It is used as a disinfectant for treating municipal water because it can kill many common pathogens present in natural freshwater sources